Multilayer ceramic capacitor

Abstract

A multilayer ceramic capacitor includes a multilayer body including dielectric layers, inner electrode layers, first and second main surfaces facing each other in a height direction, first and second side surfaces facing each other in a width direction perpendicular or substantially perpendicular to the height direction, and first and second end surfaces facing each other in a length direction perpendicular or substantially perpendicular to the height direction and the width direction, and an outer electrode layer on the multilayer body and connected to some of the inner electrode layers. When crystal orientations of crystal grains in the dielectric layers are measured by electron backscatter diffraction, two or more pairs of adjacent crystal grains between which a difference in crystal orientation is within about 5 degrees with respect to a predetermined direction in a 2 μm-square observation area are present.

What is claimed is: 
     
         1 . A multilayer ceramic capacitor comprising:
 a multilayer body including a plurality of stacked dielectric layers, a plurality of stacked inner electrode layers, a first main surface and a second main surface facing each other in a height direction, a first side surface and a second side surface facing each other in a width direction perpendicular or substantially perpendicular to the height direction, and a first end surface and a second end surface facing each other in a length direction perpendicular or substantially perpendicular to the height direction and the width direction; and   an outer electrode layer on the multilayer body and connected to some of the plurality of inner electrode layers;   when crystal orientations of crystal grains in the plurality of dielectric layers are measured by electron backscatter diffraction, in a 2 μm-square observation area, two or more pairs of adjacent crystal grains between which a difference in crystal orientation is within about 5 degrees with respect to a predetermined direction are present.   
     
     
         2 . The multilayer ceramic capacitor according to  claim 1 , wherein 20 or more pairs of adjacent crystal grains between which a difference in crystal orientation is within about 5 degrees with respect to a predetermined direction are present. 
     
     
         3 . The multilayer ceramic capacitor according to  claim 1 , wherein one or more sets of three crystal grains are present and include one crystal grain, and two crystal grains adjacent to the one crystal grain and whose misorientation angles with respect to the one crystal grain are within about 5 degrees. 
     
     
         4 . The multilayer ceramic capacitor according to  claim 1 , wherein 50 or more and 250 or less crystal grains are observed in the observation area. 
     
     
         5 . The multilayer ceramic capacitor according to  claim 1 , wherein each of the plurality of dielectric layers includes barium titanate, calcium titanate, strontium titanate, or calcium zirconate as a main component. 
     
     
         6 . The multilayer ceramic capacitor according to  claim 1 , wherein each of the plurality of dielectric layers includes a perovskite oxide including an A-site element and a B-site element as a main component. 
     
     
         7 . The multilayer ceramic capacitor according to  claim 1 , wherein a thickness of each of the plurality of dielectric layers is about 0.3 μm or more and about 10 μm or less. 
     
     
         8 . The multilayer ceramic capacitor according to  claim 1 , wherein each of the plurality of inner electrode layers includes nickel, copper, silver, palladium, or gold. 
     
     
         9 . A multilayer ceramic capacitor comprising:
 a multilayer body including a plurality of stacked dielectric layers, a plurality of stacked inner electrode layers, a first main surface and a second main surface facing each other in a height direction, a first side surface and a second side surface facing each other in a width direction perpendicular or substantially perpendicular to the height direction, and a first end surface and a second end surface facing each other in a length direction perpendicular or substantially perpendicular to the height direction and the width direction; and   an outer electrode layer on the multilayer body and connected to some of the plurality of inner electrode layers; wherein   when crystal orientations of crystal grains in the plurality of dielectric layers are measured by electron backscatter diffraction, about 2% or more of all crystal grains are crystal grains each of which is in contact with another crystal grain whose difference in crystal orientation from the corresponding crystal grain is within about 5 degrees with respect to a predetermined direction.   
     
     
         10 . The multilayer ceramic capacitor according to  claim 9 , wherein about 20% or more of all crystal grains are crystal grains each of which is in contact with another crystal grain whose difference in crystal orientation from the corresponding crystal grain is within about 5 degrees with respect to a predetermined direction. 
     
     
         11 . The multilayer ceramic capacitor according to  claim 9 , wherein each of the plurality of dielectric layers includes barium titanate, calcium titanate, strontium titanate, or calcium zirconate as a main component. 
     
     
         12 . The multilayer ceramic capacitor according to  claim 9 , wherein each of the plurality of dielectric layers includes a perovskite oxide including an A-site element and a B-site element as a main component. 
     
     
         13 . The multilayer ceramic capacitor according to  claim 9 , wherein a thickness of each of the plurality of dielectric layers is about 0.3 μm or more and about 10 μm or less. 
     
     
         14 . The multilayer ceramic capacitor according to  claim 9 , wherein each of the plurality of inner electrode layers includes nickel, copper, silver, palladium, or gold. 
     
     
         15 . A multilayer ceramic capacitor comprising:
 a multilayer body including a plurality of stacked dielectric layers, a plurality of stacked inner electrode layers, a first main surface and a second main surface facing each other in a height direction, a first side surface and a second side surface facing each other in a width direction perpendicular or substantially perpendicular to the height direction, and a first end surface and a second end surface facing each other in a length direction perpendicular or substantially perpendicular to the height direction and the width direction; and   an outer electrode layer on the multilayer body and connected to some of the plurality of inner electrode layers; wherein   a value of second average grain size/first average grain size is about 1.0 or more;   where the first average grain size is a median diameter of crystal grains in the plurality of dielectric layers determined by observation with a scanning transmission electron microscope, and the second average grain size is a median diameter of crystal grains each defining two adjacent crystal grains between which a misorientation angle is within about 5 degrees with respect to a predetermined direction when crystal orientations of the crystal grains in the dielectric layers are measured by electron backscatter diffraction.   
     
     
         16 . The multilayer ceramic capacitor according to  claim 15 , wherein each of the plurality of dielectric layers includes barium titanate, calcium titanate, strontium titanate, or calcium zirconate as a main component. 
     
     
         17 . The multilayer ceramic capacitor according to  claim 15 , wherein each of the plurality of dielectric layers includes a perovskite oxide including an A-site element and a B-site element as a main component. 
     
     
         18 . The multilayer ceramic capacitor according to  claim 15 , wherein a thickness of each of the plurality of dielectric layers is about 0.3 μm or more and about 10 μm or less. 
     
     
         19 . The multilayer ceramic capacitor according to  claim 15 , wherein each of the plurality of inner electrode layers includes nickel, copper, silver, palladium, or gold.